Open QA 8

#$&*

course Mth 163

008.

*********************************************

Question: `q001. Note that this assignment has 4 questions

For the function y = 1.1 x + .8, what are the coordinates of the x = 2 and x = 9 points? What is the rise between these points and what is the run between these points? What therefore is the slope between these points?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

Y = 1.1(2) + 8

Y = 10.2

Y = 1.1(9) + 8

Y = 17.9

(2, 10.2), (9, 17.9)

Our rise is 17.9-10.2 = 7.7

Our run is 9-2 = 7

Slope is rise/run

= 7.7/7

= 1.1

confidence rating #$&*:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

Evaluating y = 1.1 x +.8 for x = 2 and x = 9 we obtain y = 3 and y = 10.7. The graph points are therefore (2,3) and (9,10.7).

The rise between these points is 10.7 - 3 = 7.7 and the run is 9-2 = 7. Thus the slope is 7.7 / 7 = 1.1.

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary):I didn’t notice the decimal place before 8 but still got the right answer!

------------------------------------------------

Self-critique rating:

*********************************************

Question: `q002. For the function y = 1.1 x + .8, what are the coordinates of the x = a point, in terms of the symbol a? What are the coordinates of the x = b point, in terms of the symbol b?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

The y coordinate is the product of the slope of the line and A, plus the y intercept.

confidence rating #$&*:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

If x = a, then y = 1.1 x + .8 gives us y = 1.1 a + .8.

If x = b, then y = 1.1 x + .8 gives us y = 1.1 b + .8. Thus the coordinates of the x = a point are (a, 1.1 a + .8) and (b, 1.1 b + .8).

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary): Oh okay I think I see what you meant here.

------------------------------------------------

Self-critique rating:

*********************************************

Question: `q003. We see that the coordinates of the x = a point are (a, 1.1 a + .8) and (b, 1.1 b + .8). What therefore is the rise between these two points? What is the run between these two points?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

The rise is (1.1a+0.8)-(1.1b+0.8) or (1.1a-1.1b)

The run is (a-b)

The slope is (1.1a-1.1b)/(a-b)

confidence rating #$&*:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

The rise between the points is the rise from y = 1.1 a + .8 to y = 1.1 b + .8, a rise of

rise = (1.1 b + .8) -(1.1 a + .8) = 1.1 b + .8 - 1.1 a - .8 = 1.1 b - 1.1 a.

The run is from x = a to x = b, a run of

run = b - a.

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary): b-a rather than a-b, okay

------------------------------------------------

Self-critique rating:

*********************************************

Question: `q004. We see that the rise between the x = a and x = b points of the graph of y = 1.1x +.8 is 1.1 b + .8 - (1.1 a + .8), while the run is b - a. What therefore is the average slope of the graph between these points? Simplify your answer.

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution: The average will be the slope solved, (1.1b-1.1a)/ (b-a) = 1.1

confidence rating #$&*::

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

The slope is

slope = rise / run = (1.1 b - 1.1 a) / (b - a) = 1.1 (b - a) / (b - a) = 1.1.

The significance of this series of exercises is that the slope between any two points of the straight line y = 1.1 x + .8 must be 1.1, no matter whether the points are given by numbers (e.g., x = 2 and x = 9) or by symbols (x = a and x = b). Mostly

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

Self-critique (if necessary): Here I’m assuming we removed the common factor of 1.1 which allowed our b-a to cancels. Im sure I should already know this, but what was the process involved in separating the 1.1 from the numerator and leaving b-a in parenthesis???

------------------------------------------------

Self-critique rating:

@&

As long as you subtract the y coordinates in the same order as the x coordinates you'll get the right result.

However we think of 'change in' and being final value - initial value, so that order is in a sense grammatically more correct.

*@

""

"

Self-critique (if necessary):

------------------------------------------------

Self-critique rating:

""

"

Self-critique (if necessary):

------------------------------------------------

Self-critique rating:

#*&!

&#This looks good. See my notes. Let me know if you have any questions. &#